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Far as I know, Islam and Judaism have similar diet restrictions. And it's not legitimate in American law to discriminate on the basis of religion, even though it happens all the time...

  They're similar, but different.  Just as an example: Mixing milk and meat in the same meal isn't kosher, but AFAIK, it's not a violation of Muslim dietary law.  Kosher wine is obviously, kosher, but isn't halal.

  I don't think ordering a Muslim meal on a flight bars you from entry, so it's not like it's being used to discriminate.

  take care,

 Scott